Various packaging is produced with two or more chambers. This includes bottles, syringes, dispensing pumps and tubes. In most applications it is important that the components of the chambers not come into contact until the components are dispensed from the package. This is the case since in many instances the components are reactive. Consequently, the separating walls in the package must be of a high integrity. There cannot be any voids in the wall material. This then presents the problem with regard to determining if there are any voids in the walls of a finished package. This can be accomplished at an early stage in the manufacture of the packages. However, many defects in the divider walls can be caused during package making or filling. Consequently, it is preferred to test the integrity of the package after filling. It has been found that when the substances to be filled into the container are electrolytes, the integrity of the barrier wall can be tested after filling the container using the packaged substances in the testing process. The packaged substances are used as an electrolyte to provide a charge along the barrier walls.
It has been found that the divider barrier walls of packages, and in particular tube packages, conveniently can be tested as to integrity by electric potential testing techniques after the packages have been filled. A voltage potential is placed on an electrode in the substance on one side of the wall versus an electrode in the substance on an other side of the wall. The potential difference is adjusted so that the barrier divider wall material insulates the electrodes, one from the other. However, if there is a void in the wall, there is a leak of current through the barrier void with a change in potential difference. This change in potential difference then can be measured and noted to reject the container with this void containing interior wall. This is a very effective technique for the testing of multichamber tubes, and in particular, dual chamber tubes even though they are tested in a filled condition. This is the case since the test technique can be incorporated into the process of filling the tubes. That is, the barrier divider walls can be tested for voids after the filling of the tube body. Since this is the last processing step prior to the sealing and final cartoning of the tubes the test is conducted a time where any defects that are caused by handling and filling the tube can be discovered. This is a preferred time to test the tubes for defects.